The present invention relates to the detection of radio-frequency interferences. Radio-frequency interference (often also referred to as electromagnetic interference) refers to the effect of undesired energy resulting from emission, broadcasting or induction (or from a combination thereof), which can have a negative effect on the reception in a radio system. The present invention and the set of problems on which it is based are described in the following in relation to radio-frequency interferences in the field of mobile radio, but without limiting the invention thereto.
Causes of radio-frequency interferences in the field of mobile radio may be defective antennae on a mobile radio mast. To locate an interference source of this type, directional antennae are used, for example. Directional antennae are receivers having a directional receiving characteristic which is amplified as a result of the design. As a receiving antenna, a directional antenna thus concentrates the maximum receiving sensitivity thereof in a desired direction, using an opening angle that is smaller or less small depending on the application. As a result of the directional effect, the reception of signals outside the primary lobe of the electromagnetic signal is attenuated.
A directional antenna of this type is disclosed for example in DE 10 2010 051 213 A1. Using a directional antenna of this type, an interference source can be detected, and the exact GPS position can be determined by means of an installed GPS sensor.
However, even with a directional antenna equipped with a GPS sensor, and thus even if the GPS position is known, it may not be possible to find the interference source retrospectively, for example if a plurality of interference sources are positioned close together, as may be the case in urban environments. Furthermore, radio-frequency interferences also occur inside buildings, where for example there is no GPS reception.